Odd spots, fan-like and spider-shaped markings could be found on Mars' ice cap. They're quite strange, so researchers gathered to study these strange formations.

The study was co-authored by Philip Christensen from Arizona State University, while observations were made with the Thermal Emission Imaging System (THEMIS), a multi-wavelength camera on NASA's Mars Odyssey orbiter. Previously, "scientists thought the spots were patches of warm, bare ground exposed as the ice disappeared," Christensen says.

However, THEMIS revealed that the spots were "nearly as cold as the carbon dioxide ice." However, the study showed that the peculiar spots on Mars' southern ice cap are seasonal formations formed by thin layers of material. These materials are being emitted by carbon dioxide that erupt through the ice cap.

You see, the temperature in Mars during winter drops to a staggering minus 20 degrees Fahrenheit. Carbon dioxide ("Martian air"), according to Christensen, "freezes directly onto the surface of the permanent polar cap". During spring, sunlight passes through that frozen slab of carbon dioxide, such that the "ice touching the ground" immediately reverts to gas.

This "warmed material" releases pressurized gas, and the weak spots on the frozen slab break, enabling high-pressure gas to "shoot up at speeds of almost 100mph." The high-pressure gas is the culprit for the mysterious Martian markings: "the large particles land around vents to make the spots, while the lighter sand grains blow downwind, creating the fans."